Drill-gage.



R. DAUGHERTY.

DRILL GAGE.

APPLICATION FILED SEPT. 26, 1910.

1,002,502. Patented Sept. 5,1911.

Attorneys REIL DAUGHER'IY, 0F HARRISBURG, PENNSYLVANIA.

DRILL-GAGE.

Specification of Letters Patent.

Patented Sept. 5, 1911.

Application filed September 26, 1910. Serial No. 583,902.

1 0 all whom it may concern:

' Be it known that I, REIL DAUGHERTY, a citizen of the United States,residing at Harrisburg, in the county of Dauphin and State ofPennsylvania, have invented a new and useful Drill-Gage, of which thefollowing is a specification.

This invention belongs to the art of drills, and it more especiallyrelates to new and useful means applicable to counter-bores, in order topermit mechanics to retain the depths of counter-bores at a uniformity.

The primary object of the invention is to provide a device of thisdesign, in which there is involved various novel features ofconstruction.

It will be remembered, however, that all counter-bores are formed withsmall lugs or teats (which are integral with the tool), in order toretain the counter-bore centered with regard to the drilled hole; butwhen the drilled hole varies slightly in diameter and depth, a difierentcounterbore has to be utilized to fit the same. This inconvenienceutilizes considerable time, and one of the objects of the invention isto obviate this ditliculty. Moreover, prior to this invention, there wasno way in retaining to a certainty, the predetermined depth ofcounterbores, and where there were a number of counter-bores to bebored, there was no way of holding them at a uniform depth.

The invention in its broadest aspect aims as these primary objects, toprovide means to overcome the above enumerated difiiculties, and to holdthe counter-bores at a uni formity. There is provided a plurality ofscrew members, such as shown in Fig. 4c, having heads of diiferentdepths and diameters, any one of which may be used in a manner as shownin Fig. 2.

In using a device of this character, the material to be worked upon isplaced upon a base or bench as shown at a in Fig. 2, after which a screwhaving a head, the diameter of which corresponds to the diameter of thehole Z) in the material cis threaded into the boring end of the tool, sothat the head of the screw is brought in close contact with the lowerextremity of the counter-bore 1. The depth of the head of the screwcorresponds in depth to the counter-bore which is desired in thematerial, as shown in dotted lines at e in Fig. 2. After motion isimparted to the tool, the same will cut into the material until the head7 of the screw contacts with the upper surface of the bench or base, onwhich the material is arranged. When the head 7 contacts with the benchor base, the cutting action of the tool ceases. It will be observed thatin this man ner a number of counter-bores may be cut or bored, all ofwhich may have a uniform depth. By turning the screw in close contactwith the lower extremity of the counterbore the same is held securely inplace, as shown in the sectional View of the drawings. When disposingthe screw in the manner shown in Fig. 2, the same should be arrangedexactly concentric with the center of the counter-bore or tool, so thatthe tool will assume a position exactly concentric with the hole Z) inthe material a, as shown in Fig. 2.

The invention aims as a further object to provide one or more screws,the heads of which vary in depth and in diameters, so that counter-boresof various depths may be bored. When it is desired to drill acounterbore of a certain depth, a screw including a head of the desireddepth and diameter is inserted in the extreme portion of thecounter-bore, then the tool is disposed until the end arranges solidadjacent a plate or base, as shown in Fig. 2, in which the work is beingaccomplished, after which one proceeds in the usual manner. In thedrawings, how ever, there is only disclosed one form of the invention,but in practical fields this form may necessitate slight alterations, towhich the applicant is entitled, provided the alterations arecomprehended by the appended claim.

Other features and combination of parts will be hereinafter more fullyset forth, shown in the drawings and claim.

In the drawings: Figure 1 is a perspective View, showing the applicationof the invention. Fig. 2 is a sectional View through the counter-bore.Fig. 3 is an end View of the counter-bore showing the application of theinvention. Fig. 1 is a View showing a plurality of screws, each having ahead of a different size.

In regard to the drawings, 1 designates the usual form of counter-bore,having the usual form of cutting edges and angles, 3, 4: and 5, as shownin Fig. 1.

Referring to the sectional View of the drawing, it will be observed thatthe counterbore is provided with a threaded bore 45, the depth of whichmay be varied, in accordance with the practical demands in the trade.Furthermore, as shown in the sectional view, there will be seen a screw6, having the usual form of threads to engage the threads of the bore ofthe counter-bore. It will be further observed that the head 7 of thescrew is of a diameter less than the diameter of the smaller portionofthe counter-bore, in order to provide a shoulder 8, whereby a mechanicwill be permitted to obtain an efiective cutting edge, by placing theshoulder adjacent the material, in which the counter-bore is desired.

It will be manifest that anyone of the screws shown in the drawings maybe utilized, there being no restriction as to the diameters and depthsof screw heads in so far as the present invention is concerned. It willbe observed from the foregoing, in connection with the annexed drawings,that novel means have been devised whereby the depth of a counter-borecan be regulated.

Noting Fig. 3, it will be seen that when the screw 6 is rotated to afirm seat, the head 7 of the screw will abut against the ends of thecutting ribs 3, at the same time that the opposite end of the screwabuts against the tool at the base of the bore 4?. By reason of thisconstruction, the head 7 0f the screw will be prevented from coming tooclosely into contact with the ends of the cutting ribs 3, a contingencylikely to dull the end edges of the cutting ribs, and to render thescrew 6 difiicult to remove, owing to the fact that the ribs 3 tend tobite into the head 7 of the screw. Moreover, referring to Fig. 3, itwill be seen that when the screw 6 is rotated to a firm seat, the kerfin the screw will be so positioned that its ends will be located betweenthe ribs, whereby a screwdriver may be reciprocated in the kerf,longitudinally of the kerf, to clear the same of accumulated material,without striking the cutting ribs 3.

The invention having been set forth,what

is claimed as new and useful is:

A boring tool having a central, threaded opening and radial cutting ribsabout the opening; and a headed screw having a kerf, and adapted to bethreaded into the opening, the screw abutting against the tool at boththe headed end and the opposite end of the screw, whereby to prevent anundue compression of the head of the screw against the ends of the ribs;the engagement between the screw and the tool, when the screw is firmlyseated, serving to position the kcrf with its ends between the ribs,whereby a screw driver may be reciprocated in the kerf, longitudinallyof the kerf, to clean the same of accumulated material, without strikingthe ribs.

In testimony that I claim the foregoing as my own, I have hereto affixedmy signature in the presence of two witnesses.

REIL DAUGHERTY. Witnesses E. WV. MILLER, A. F. OHENM.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

